Page:Popular Science Monthly Volume 7.djvu/778

758 clumsily. Try to flex a single toe, keeping the rest straight, and the thing will be found to be impossible; they all move together. The big toe may have a little independence, but not much. The Duke of Argyll has lately said, that we can know the animal by looking down from our higher selves upon our lower selves. If the duke would look at an opossum flexing its toes in climbing, and then look down on his own foot, he would have a closer acquaintance with the marsupial. Our toes have the same communal movements as those of the opossum. But our fingers we can flex one at a time or any way we like.

Now, Dr. Barnard's dissections would seem to show that the muscles which move the fingers and toes have been differentiated from one (communis) muscle. He has found many stages of differentiation. The flexor which inserts in the thumb of man inserts in two or three toes in the higher apes. The extensor of the index-finger is the same in the gorilla as in man, but in the lower apes and lemurs it has two parts. In lemurs the third finger gets a tendon from the extensor of the index. In all apes the extensor muscle of the third finger is inconstant. On the theory that the proprius muscles, the flexors and extensors of the fingers and toes, have been developed by specialization out of one communis muscle, these facts and many others of the same kind are luminous; on any other theory they are inexplicable. In the foot, man remains a creature of the past, not modified by that which makes him a man, the brain. The hand has been modified and perfected by its services to the brain.

The Orang and Man.—Dr. Barnard's paper on "The Myology of Simia satyrus" was based on a dissection he had made of an orang at Cornell University, and dissections of lower apes recently made in Germany. When, in 1818, Traill dissected one of the higher apes, he found a muscle which he homologized with the gluteus minimus (one of the abductor muscles of the thigh) in man. Other muscles in the same region he supposed to represent similar muscles in man. But one muscle he found in the ape, which he thought had no representative in man, and this he named the scansorius, or "climbing-muscle." Traill was followed by Owen, Wyman, Wilder, and by Bischoff, who, in his controversy with Huxley, argued from this muscle against a simian ancestry for man. Dr. Barnard shows that Traill was mistaken, and that the other great anatomists were misled by the weight of his authority. What Traill took to be the gluteus minimus is the pyriformis, and what he figured as a new muscle separating the apes from man, the scansorius, is the homologue of our gluteus minimus. In the orang, Dr. Barnard finds a muscle which has no homologue in man. It is a mere vestige. It occurs in some of the lower apes, as the lemurs, but has no functional value. It is found in the opossum, but no longer as a vestige. Thus when we go back as far as the marsupials, this muscle, which in man is obsolete, almost obsolete in the higher apes, less aborted in the lower apes, is an active organ, performing certain functions. In the orang the two external muscles of the calf do not unite to form one tendon, tendon Achillis, as in man. Now, this double tendon Achillis sometimes occurs in marsupials. These researches go far to prove that the muscles of man can be traced backward through the apes to the lemurs, and through them to the marsupials.

The Study of Mathematics.—Prof H. A. Newton, vice-president of Section A, at the Detroit meeting, advocated in his address a wider and deeper study of mathematics by American men of science. American contributions to the science of quantity have not been large; take away from their number three or four volumes, a dozen memoirs, and here and there a fruitful idea, and there is very little left that the world will care to remember. True, excellent text-books have been made here; but Prof. Newton is speaking of additions to our knowledge and not of the arrangement of it. The idea seems to be quite general among us that the mathematics is a finished science, and that it has few fertile fields inviting labor, and few regions to be explored. And yet hardly any science can show on the whole a more steady progress for the last fifty years, or a larger and healthier growth, than the science of quantity. The scientific investigator finds himself again and again arrested in his